Electro-phoretic display apparatus

ABSTRACT

An electro-phoretic display apparatus including an electro-phoretic display panel and a driving circuit is provided. The electro-phoretic display panel includes a display area and a border area. The driving circuit is configured to drive the display area to display an image frame according to a first voltage. The driving circuit drives the border area to maintain displaying a border of a first color or a second color according to a second voltage. The driving circuit generates the second voltage according to the first voltage. The border area includes electro-phoretic particles of the first color or the second color. A voltage difference between the first voltage and the second voltage drives the electro-phoretic particles of the first color or the second color to be maintained to a predetermined position such that the border area maintains displaying the border of the first color or the second color.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims thepriority benefit of a prior application Ser. No. 15/826,684, filed onNov. 30, 2017, now pending. The prior application claims the prioritybenefit of China application serial no. 201611087805.X, filed on Dec. 1,2016. The entirety of the above-mentioned patent application is herebyincorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a display apparatus, and particularly relatesto an electro-phoretic display apparatus.

Description of Related Art

Generally, applications of electro-phoretic display apparatus aredivided into two types. One type is to connect an electro-phoreticdisplay panel to a predetermined driving voltage, such that an imagethereof may flash black and flash white along with a variation of thedriving voltage. Another type of the application is to connect a borderarea of the electro-phoretic display panel to a common electrodevoltage, such that a display color thereof is not changed to maintain apredetermined border color. Although the later type may decrease circuitcomplexity of a system end, since the border area connected to thecommon electrode voltage is easy to produce a gray border phenomenon, itmay cause a distortion phenomenon.

SUMMARY OF THE INVENTION

The invention is directed to an electro-phoretic display apparatus,which may mitigate a distortion phenomenon of a border area thereof.

The invention provides an electro-phoretic display apparatus includingan electro-phoretic display panel and a driving circuit. Theelectro-phoretic display panel includes a display area and a borderarea. The driving circuit is coupled to the electro-phoretic displaypanel. The driving circuit is configured to drive the display area todisplay an image frame according to a first voltage. The driving circuitdrives the border area to maintain displaying a border of a first coloror a second color according to a second voltage. The driving circuitgenerates the second voltage according to the first voltage. The borderarea includes electro-phoretic particles of the first color or thesecond color. A voltage difference between the first voltage and thesecond voltage drives the electro-phoretic particles of the first coloror the second color to be maintained to a predetermined position suchthat the border area maintains displaying the border of the first coloror the second color.

In an embodiment of the invention, the driving circuit drives the borderarea to maintain displaying the border of the second color according tothe second voltage. The driving circuit increases an absolute value ofthe first voltage to produce an absolute value of the second voltage,and the absolute value of the second voltage is higher than the absolutevalue of the first voltage.

In an embodiment of the invention, the driving circuit includes anoperation amplifier, a first resistor and a second resistor. Theoperation amplifier has a first input terminal, a second input terminaland an output terminal. The first input terminal of the operationamplifier receives the first voltage. The output terminal of theoperation amplifier outputs the second voltage. The first resistor has afirst terminal and a second terminal. The first terminal of the firstresistor is coupled to the output terminal of the operation amplifier.The second terminal of the first resistor is coupled to the second inputterminal of the operation amplifier. The second resistor has a firstterminal and a second terminal. The first terminal of the secondresistor is coupled to the second input terminal of the operationamplifier, and the second terminal of the second resistor is coupled toa ground voltage.

In an embodiment of the invention, the driving circuit drives the borderarea to maintain displaying the border of the first color according tothe second voltage. The driving circuit decreases an absolute value ofthe first voltage to produce an absolute value of the second voltage,and the absolute value of the second voltage is lower than the absolutevalue of the first voltage.

In an embodiment of the invention, the driving circuit includes a firstresistor and a second resistor. The first resistor has a first terminaland a second terminal. The first terminal of the first resistor receivesthe first voltage. The second terminal of the first resistor outputs thesecond voltage. The second resistor has a first terminal and a secondterminal. The first terminal of the second resistor is coupled to thesecond terminal of the first resistor. The second terminal of the secondresistor is coupled to a ground voltage.

In an embodiment of the invention, the first voltage and the secondvoltage are negative voltages.

In an embodiment of the invention, the first voltage is a commonelectrode voltage of the display area.

In an embodiment of the invention, the driving circuit is disposed onthe electro-phoretic display panel.

In an embodiment of the invention, the driving circuit is disposedoutside the electro-phoretic display panel.

According to the above description, in the exemplary embodiment of theinvention, the driving circuit drives the border area of theelectro-phoretic display panel according to the second voltage, so as tomitigate the distortion phenomenon.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram of an electro-phoretic display apparatusaccording to an embodiment of the invention.

FIG. 2 is a schematic diagram of an internal circuit structure of adriving circuit according to an embodiment of the invention.

FIG. 3 is a waveform schematic diagram of a first voltage and a secondvoltage of the embodiment of FIG. 2.

FIG. 4 is a schematic diagram of an internal circuit structure of adriving circuit according to another embodiment of the invention.

FIG. 5 is a waveform schematic diagram of a first voltage and a secondvoltage of the embodiment of FIG. 4.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic diagram of an electro-phoretic display apparatusaccording to an embodiment of the invention. Referring to FIG. 1, theelectro-phoretic display apparatus 100 of the present embodimentincludes an electro-phoretic display panel 110 and a driving circuit120. The electro-phoretic display panel 110 includes a display area AAand a border area BD. The driving circuit 120 is coupled to theelectro-phoretic display panel 110. The driving circuit 120 drives thedisplay area AA to display an image frame according to a first voltageV1. The driving circuit 120 drives the border area BD to maintaindisplaying a white border or a black border according to a secondvoltage V2. In the present embodiment, the first voltage V1 is, forexample, a common electrode voltage used for driving the display area AAto display the image frame.

In the present embodiment, the driving circuit 120 is, for example, anexternal circuit independently disposed outside the electro-phoreticdisplay panel 110. Alternatively, in an embodiment, the driving circuit120 is, for example, an internal circuit disposed on a peripheralcircuit configuration area (not shown) of the electro-phoretic displaypanel 110. The configuration position of the driving circuit 120 is notlimited by the invention.

FIG. 2 is a schematic diagram of an internal circuit structure of thedriving circuit according to an embodiment of the invention. FIG. 3 is awaveform schematic diagram of the first voltage and the second voltageof the embodiment of FIG. 2. Referring to FIG. 2 and FIG. 3, the drivingcircuit 220 of the present embodiment, for example, generates the secondvoltage V2 according to the first voltage V1. The first voltage V1 is,for example, the common electrode voltage used for driving the displayarea AA to display the image frame.

In the present embodiment, the driving circuit 220 includes an operationamplifier 222, a first resistor R1 and a second resistor R2. Theoperation amplifier 222 has a first input terminal (a non-inverted inputterminal), a second input terminal (an inverted input terminal) and anoutput terminal. The first input terminal of the operation amplifier 222receives the first voltage V1. The second input terminal of theoperation amplifier 222 is coupled to a second terminal of the firstresistor. The output terminal of the operation amplifier 222 outputs thesecond voltage V2. The first resistor R1 has a first terminal and thesecond terminal. The first terminal of the first resistor R1 is coupledto the output terminal of the operation amplifier 222. The secondterminal of the first resistor R1 is coupled to the second inputterminal of the operation amplifier 222. The second resistor R2 has afirst terminal and a second terminal. The first terminal of the secondresistor R2 is coupled to the second input terminal of the operationamplifier 222, and the second terminal of the second resistor R2 iscoupled to a ground voltage GND.

In the present embodiment, the operation amplifier 222 of the drivingcircuit 220, for example, has a circuit configuration of an in-phaseamplifier. The operation amplifier 222 feeds back the second voltage V2to the second input terminal thereof, such that the first voltage V1 andthe second voltage V2 are the same. By using the in-phase amplifier, anabsolute value of the first voltage V1 is increased to an absolute valueof the second voltage V2, such that electro-phoretic particles aremaintained to a predetermined position thereof. Therefore, in thepresent embodiment, the driving circuit 220 increases the absolute valueof the first voltage V1 to produce the absolute value of the secondvoltage V2, so that the absolute value of the second voltage V2 ishigher than the absolute value of the first voltage V1. For example, inthe present embodiment, the driving circuit 220, for example, adjuststhe first voltage V1 of −2 volts (V) to the second voltage V2 of −3 V.The first voltage V1 and the second voltage V2 are all negativevoltages, and the absolute value of the second voltage V2 is higher thanthe absolute value of the first voltage V1. In the present embodiment,the first voltage V1 of −2 V and the second voltage V2 of −3 V are onlyused as an example, and voltage values thereof are not limited by theinvention.

In the present embodiment, the driving circuit 220, for example, drivesthe border area BD to maintain displaying the white border according tothe second voltage V2. When the border area BD of the electro-phoreticdisplay panel 110 is driven to display a white color, the drivingcircuit 220 outputs the second voltage V2 to the border area BDaccording to the first voltage V1, for example, adjusts the firstvoltage V1 of −2 V to the second voltage V2 of −3 V. Based on a voltagedifference between the first voltage V1 and the second voltage V2, thewhite electro-phoretic particles are maintained to the predeterminedposition thereof, such that the border area BD maintains displaying thewhite border without distortion. Therefore, the border area BDmaintaining displaying the white border may enlarge a visual effect of aviewing zone of the display area AA with a white background.

FIG. 4 is a schematic diagram of an internal circuit structure of thedriving circuit according to another embodiment of the invention. FIG. 5is a waveform schematic diagram of the first voltage and the secondvoltage of the embodiment of FIG. 4. Referring to FIG. 4 and FIG. 5, thedriving circuit 320 of the present embodiment, for example, generatesthe second voltage V2 according to the first voltage V1. The firstvoltage V1 is, for example, a common electrode voltage used for drivingthe display area AA to display the image frame.

In the present embodiment, the driving circuit 320 includes a firstresistor R1 and a second resistor R2. A first terminal of the firstresistor R1 receives the first voltage V1. A second terminal of thefirst resistor R1 outputs the second voltage V2. The second resistor R2has a first terminal and a second terminal. The first terminal of thesecond resistor R2 is coupled to the second terminal of the firstresistor R1. The second terminal of the second resistor R2 is coupled tothe ground voltage GND.

In the present embodiment, a combination of the first resistor R1 andthe second resistor R2 of the driving circuit 320, for example, has acircuit configuration of a voltage-divining circuit. The combination ofthe first resistor R1 and the second resistor R2 divides the firstvoltage V1 to produce the second voltage V2, and the first voltage V1 issame to the second voltage. By using the voltage-dividing circuit, theabsolute value of the first voltage V1 is decreased to the absolutevalue of the second voltage V2, such that the electro-phoretic particlesare maintained to a predetermined position thereof. Therefore, in thepresent embodiment, the driving circuit 320 decreases the absolute valueof the first voltage V1 to produce the absolute value of the secondvoltage V2, so that the absolute value of the second voltage V2 is lowerthan the absolute value of the first voltage V1. For example, in thepresent embodiment, the driving circuit 320, for example, adjusts thefirst voltage V1 of −2 volts (V) to the second voltage V2 of −1 V. Thefirst voltage V1 and the second voltage V2 are all negative voltages,and the absolute value of the second voltage V2 is lower than theabsolute value of the first voltage V1. In the present embodiment, thefirst voltage V1 of −2 V and the second voltage V2 of −1 V are only usedas an example, and voltage values thereof are not limited by theinvention.

In the present embodiment, the driving circuit 320, for example, drivesthe border area BD to maintain displaying the black border according tothe second voltage V2. When the border area BD of the electro-phoreticdisplay panel 110 is driven to display a back color, the driving circuit320 outputs the second voltage V2 to the border area BD according to thefirst voltage V1, for example, adjusts the first voltage V1 of −2 V tothe second voltage V2 of −1 V. Based on a voltage difference between thefirst voltage V1 and the second voltage V2, the black electro-phoreticparticles are maintained to the predetermined position thereof, suchthat the border area BD maintains displaying the black border withoutdistortion. Therefore, based on the border area BD maintainingdisplaying the black border, the border area BD serving as an alignmentarea may provide a clear position.

In summary, in the exemplary embodiment of the invention, the drivingcircuit drives the border area of the electro-phoretic display panel todisplay the white border or the black border according to the secondvoltage, so as to avoid a situation that the border area displays a graycolor, and mitigate the distortion phenomenon.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. An electro-phoretic display apparatus,comprising: an electro-phoretic display panel, comprising a display areaand a border area; and a driving circuit, coupled to theelectro-phoretic display panel, and configured to drive the display areato display an image frame according to a first voltage, and drive theborder area to maintain displaying a border of a first color or a secondcolor according to a second voltage, wherein the driving circuitgenerates the second voltage according to the first voltage, the borderarea includes electro-phoretic particles of the first color or thesecond color, and a voltage difference between the first voltage and thesecond voltage drives the electro-phoretic particles of the first coloror the second color to be maintained to a predetermined position suchthat the border area maintains displaying the border of the first coloror the second color.
 2. The electro-phoretic display apparatus asclaimed in claim 1, wherein the driving circuit drives the border areato maintain displaying the border of the second color according to thesecond voltage, and the driving circuit increases an absolute value ofthe first voltage to produce an absolute value of the second voltage,wherein the absolute value of the second voltage is higher than theabsolute value of the first voltage.
 3. The electro-phoretic displayapparatus as claimed in claim 2, wherein the driving circuit comprising:an operation amplifier, having a first input terminal, a second inputterminal and an output terminal, wherein the first input terminal of theoperation amplifier receives the first voltage, and the output terminalof the operation amplifier outputs the second voltage; a first resistor,having a first terminal and a second terminal, wherein the firstterminal of the first resistor is coupled to the output terminal of theoperation amplifier, and the second terminal of the first resistor iscoupled to the second input terminal of the operation amplifier; and asecond resistor, having a first terminal and a second terminal, whereinthe first terminal of the second resistor is coupled to the second inputterminal of the operation amplifier, and the second terminal of thesecond resistor is coupled to a ground voltage.
 4. The electro-phoreticdisplay apparatus as claimed in claim 1, wherein the driving circuitdrives the border area to maintain displaying the border of the firstcolor according to the second voltage, and the driving circuit decreasesan absolute value of the first voltage to produce an absolute value ofthe second voltage, and the absolute value of the second voltage islower than the absolute value of the first voltage.
 5. Theelectro-phoretic display apparatus as claimed in claim 4, wherein thedriving circuit comprises: a first resistor, having a first terminal anda second terminal, wherein the first terminal of the first resistorreceives the first voltage, and the second terminal of the firstresistor outputs the second voltage; and a second resistor, having afirst terminal and a second terminal, wherein the first terminal of thesecond resistor is coupled to the second terminal of the first resistor,and the second terminal of the second resistor is coupled to a groundvoltage.
 6. The electro-phoretic display apparatus as claimed in claim1, wherein the first voltage and the second voltage are negativevoltages.
 7. The electro-phoretic display apparatus as claimed in claim1, wherein the first voltage is a common electrode voltage of thedisplay area.
 8. The electro-phoretic display apparatus as claimed inclaim 1, wherein the driving circuit is disposed on the electro-phoreticdisplay panel.
 9. The electro-phoretic display apparatus as claimed inclaim 1, wherein the driving circuit is disposed outside theelectro-phoretic display panel.